Description
This detector identifies the use of software-based audio drivers in place of physical audio hardware, such as built-in laptop speakers, microphones, or external USB headsets.
Virtual audio devices intercept, emulate, or reroute audio input and output through software interfaces. When accessed through a browser, these devices expose technical characteristics that differ from physical sound hardware.
Detection is based on multiple audio and device indicators, including:
Driver identification
The browser reports audio input or output devices with names commonly associated with virtual audio drivers, such as VB-Audio, Virtual Cable, BlackHole, or Loopback, rather than hardware manufacturers like Realtek, Intel, or Apple.
Missing or simplified hardware capabilities
Virtual audio drivers often lack the full range of supported sample rates, buffer sizes, or channel configurations typically present in physical sound cards.
Silent or headless audio profiles
Devices that claim to be laptops or workstations but expose no detectable audio input or output capabilities, a pattern frequently observed in servers, virtual machines, or headless attack environments.
Relevance to Social Engineering Attacks
In modern social engineering campaigns, audio has become a primary attack vector, particularly in environments that rely on real-time voice interaction for trust and verification.
Common attacker use cases include:
Deepfake and voice injection attacks
Virtual audio cables allow attackers to route AI-generated or pre-recorded voices directly into browser-based communication platforms such as Zoom, Microsoft Teams, or WebRTC-powered help desk portals. Instead of speaking live, the attacker plays a synthetic or impersonated voice through the virtual driver.
Call interception and covert recording
Software-based audio routing enables silent recording of verification calls or help desk interactions. Attackers can later analyze these recordings to refine scripts, anticipate security questions, or train automated systems for future attempts.
Remote and virtualized fraud operations
Many organized fraud centers operate from virtualized desktop environments that lack physical sound hardware. These environments rely entirely on virtual audio drivers to route audio between the attacker’s headset and the target application, making virtual audio a common characteristic of large-scale social engineering operations.
Examples of Detected Tooling and Techniques
This detector is effective against a range of audio routing and manipulation tools, including:
Virtual audio cable drivers
VB-Audio Cable, VAC (Virtual Audio Cable).
Audio routing and mixing software
Loopback (macOS), VoiceMeeter, BlackHole.
AI and voice manipulation tools
Software that intercepts microphone input to replace or augment live speech with AI-generated or pre-recorded audio.